How to achieve functional cure of HBV: Stopping NUCs, adding interferon or new drug development?

The significance of antibody to hepatitis B surface antigen in infection and clearance of hepatitis B virus

One of the key features of chronic hepatitis B virus (HBV) infection is the inability to mount sufficient and coordinated adaptive immune responses against HBV. Recent studies on HBV-specific B cells and antibody to hepatitis B surface antigen (anti-HBs) have shed light on their role in the pathogenesis of chronic hepatitis B (CHB). Anti-HBs is recognized as a protective immune marker, both for HBV infection clearance and following vaccination, and it is also considered an important indicator of functional cure for CHB. Notably, functional impairment of HBV-specific B cells may be reversible. The restoration of HBV-specific B cell function, along with the induction of an anti-HBs antibody response, is regarded as pivotal for terminating chronic HBV infection and achieving functional cure. This article reviews the significance of anti-HBs in both the infection and clearance of HBV, and discusses the potential of neutralizing antibodies and therapeutic vaccines as promising future strategies.

Mechanisms underlying delayed loss of HBeAg and HBV DNA following HBsAg seroclearance in PEG-IFNα treated patients of chronic hepatitis B

BACKGROUND & AIMS

A notable proportion of CHB patients undergoing PEG-IFNα based therapy experience lagged serum HBeAg and/or HBV DNA disappearance in patients achieving HBsAg loss. In this study, we explored the molecular mechanisms behind this clinical phenomenon, offering novel insights into the sustainability of chronic HBV infection.

METHODS

Two independent clinical cohorts were enrolled to validate this phenomenon. Then comprehensive analysis was performed using public datasets, coupled with a series of molecular biology experiments.

RESULTS

Approximately 17-20% CHB patients underwent PEG-IFNα based therapy experienced seroclearance of HBsAg, while serum HBeAg and/or HBV DNA remained positive. These patients are more prone to serum HBsAg reappearance compared to those achieving complete virological response. Analysis of public datasets revealed that compared to the PC/BCP, the SP1/SP2 promoter displayed more pronounced inhibitory epigenetic modifications in HBeAg-negative patients and SP1/SP2 in-frame mutation peaked in immune active patients. In vitro experiments demonstrated that introduced SP1/SP2 inactive mutations would enhance PC/BCP transcriptional activity by a mechanism known as adjacent transcriptional interference. Furthermore, the deletion of L-HBsAg facilitated intracellular cccDNA replenishment.

CONCLUSION

This study elucidates that under IFNα treatment and low viral load, transcriptional suppression of SP1/SP2 promoters through mutations and/or epigenetic changes would favour the maintenance of sustain chronic HBV infection, via enhancing the transcription activity of BCP to promote cccDNA replenishment.

IMPACT AND IMPLICATIONS

In clinical practice with IFNα antiviral treatment for CHB patients, a "paradoxical" phenomenon is observed where serum HBsAg disappears while HBV DNA or/and HBeAg remains at low positive levels, with delayed disappearance. Our study confirms this clinical phenomenon using two independent clinical cohorts and explores the potential mechanisms behind the persistence of chronic HBV infection under IFNα treatment and low viral load. Transcriptional suppression of SP1/SP2 promoters through mutations and/or epigenetic changes supports the maintenance of chronic HBV infection by enhancing the transcriptional activity of the BCP, which in turn promotes cccDNA replenishment.

HighlightsApproximately 20% of patients with CHB who have just achieved HBsAg loss under IFNα treatment show positive serum HBV DNA and/or HBeAg.During disease progression, in frame indel mutations accumulate in the HBV genome's SP1 and SP2 promoters, with epigenetic modifications contributing to their suppression.In frame indel mutations in the HBV genome's SP1 and SP2 promoters inhibit the transcription of HBV S mRNA and promote the transcription of 3.5 kb HBV RNA.The loss of L-HBs and envelop proteins leads to an increase in intracellular cccDNA, promoting the maintenance of chronic infection.

Scoping Review on Strategies for Safe Nucleot(s)ide Analogue Discontinuation and Optimising Functional Cure in Chronic Hepatitis B

Chronic hepatitis B (CHB) remains a global health challenge, contributing to significant morbidity and mortality. While long-term nucleos(t)ide analogue (NA) therapy effectively suppresses viral replication, achieving a functional cure remains rare. Current treatment guidelines primarily recommend indefinite therapy. However, long-term NA use poses many challenges, prompting interest in finite therapy. Recent studies suggest that carefully selected patients may safely discontinue NAs, leading to a functional cure in some cases. This review evaluates the latest evidence on NA discontinuation, highlighting key factors influencing outcomes. This review synthesises established and emerging evidence on NA discontinuation in CHB. It explores early studies that identified quantitative HBsAg (qHBsAg) as a predictor of sustained response and HBsAg seroclearance, followed by systematic reviews and meta-analyses reinforcing finite therapy as a feasible approach. Advances in predictive modelling, incorporating biomarkers, have refined patient selection for safe NA withdrawal. Additionally, this review assesses the risks associated with NA discontinuation, highlighting the importance of identifying high-risk patients for hepatic decompensation. Ethnicity-specific qHBsAg cut-offs are also discussed, recognising variations in treatment response between Asian and Caucasian populations. Finite NA therapy is emerging as a viable approach for achieving functional cure. Future strategies should integrate liver fibrosis assessment to enhance patient selection before NA discontinuation. Optimising re-treatment approaches requires balancing timing, immune response, and qHBsAg kinetics to maximise HBsAg seroclearance. Clinical perspectives on NA discontinuation remain a key research priority, necessitating standardised guidelines and improved post-NA monitoring strategies to ensure safe and effective finite therapy in CHB management.

Unmet needs in the clinical management of chronic hepatitis B infection

The hepatitis B virus (HBV) remains a global problem despite effective tools to prevent, diagnosis, and control it. Unmet needs are identifiable across its clinical care cascade, underlining the challenges providers face in delivering effective care for patients with chronic hepatitis B. The review herein will focus on three timely clinical issues in HBV. This includes efforts to optimize delivery of perinatal HBV care, improve HBV-related hepatocellular carcinoma risk stratification models, and clarify the role of finite therapy in the HBV treatment algorithm. Important developments within these three topics will be addressed with the goal to motivate further investigation and optimization of these treatment strategies for HBV.

Dynamics of HBV biomarkers during nucleos(t)ide analog treatment: A 14-year study

BACKGROUND

Circulating HBsAg, HBV RNA, and hepatitis B core-related antigen (HBcrAg) are potential biomarkers for the response to nucleos(t)ide analog (NA) treatment discontinuation in patients with chronic hepatitis B (CHB). We retrospectively investigated the long-term kinetics of HBsAg, HBV RNA, and HBcrAg in HBeAg-negative patients treated with NA for up to 14 years in a prospective cohort study.

METHODS

Ninety-six patients (mean age 65 y, 77% male, 52% with cirrhosis, all HBV genotype D) who were undergoing first (n=33, group A) or second-line (n=63, group B) treatment with tenofovir disoproxil fumarate were included. HBV biomarkers collected during tenofovir disoproxil fumarate treatment were measured in 384 serum samples stored at -20 °C. The combined biomarker endpoints associated with functional cure following NA discontinuation included HBsAg <1000 IU/mL, HBV RNA <54 copies/mL, and HBcrAg <2 log U/mL.

RESULTS

Before NA treatment, HBV RNA and HBcrAg were detectable in 85% (mean 3.9±2.3 [range, 0-9.2] log10 copies/mL) and 80% (mean 4.3±1.9 [2-8.9] log10 U/mL), respectively, of the patients in group A. In groups A and B, the percentages of patients with detectable HBV RNA levels decreased to 53% and 34%, respectively, during years 8-10 of NA treatment, and to 29% in group B during years 11-14 to 29%. HBcrAg could be quantified in 2% of patients in group B NA treatment years 8-10. Combined biomarker endpoints were met at baseline and at years 1-4, 5-7, 8-10, and 11-14 of treatment by 3.3%, 12% and 14%, 13% and 38%, 26% and 29%, and 41% of patients, respectively.

CONCLUSIONS

HBV biomarker endpoints are associated with functional cure after the discontinuation of NA increase during long-term NA treatment.

Depalmitoylase ABHD16A negatively regulates the anti-hepatitis B virus activity of IFITM1

Interferon-inducible transmembrane (IFITM) proteins have been widely reported as antiviral factors against various viral pathogens. However, the mechanisms of IFITM regulation on hepatitis B virus (HBV), which induces chronic infection resulting in cirrhosis as well as liver cancer, remain poorly characterized. In the present study, we identified that HBV infection significantly increased the expression of IFITM1. To dissect the role of IFITM1 in HBV infection, we overexpressed IFITM1 in HepG2.215 cells and revealed that the replication of HBV was restricted by IFITM1. Recently, we demonstrated that the anti-RNA virus activity of IFITM proteins depends on palmitoylation modification, and the depalmitoylase α/β-hydrolase domain-containing 16A (ABHD16A) negatively regulates IFITM1 against RNA virus infection in human and porcine cells. However, whether ABHD16A-IFITM1 regulates DNA virus infection has not been researched. Here, by using co-immunoprecipitation (Co-IP) and acyl-PEGyl exchange gel-shift assay, ABHD16A-catalyzed depalmitoylation of IFITM1 was verified in HepG2.215 cells. In addition, we respectively knocked out IFITM1 and ABHD16A via CRISPR/Cas9 and showed that the anti-HBV activity of IFITM1 was negatively regulated by ABHD16A through depalmitoylation. Collectively, our findings demonstrated for the first time that ABHD16A catalyzes the depalmitoylation of IFITM1 to regulate its antiviral activity against HBV, which expands the biological functions of ABHD16A in immune regulation and provides potential targets for HBV infection-related disease therapy.IMPORTANCENowadays, hepatitis B virus (HBV) infection remains a major global public health problem, with over 375 million people worldwide having been infected. Chronic HBV infection leads to serious liver diseases, such as liver cirrhosis and hepatocellular carcinoma. Therefore, it is urgent to reveal the mechanism of HBV infection and uncover novel drug targets. Interferon and interferon-stimulated genes are responsible for the inhibition of HBV infection. Interferon-inducible transmembrane (IFITM) is distributed on plasma membrane, restricting various virus invasions. Nevertheless, whether and how IFITM regulates HBV infection remains unclear. Here, we show that IFITM1 inhibited the replication of HBV, which depended on palmitoylation modification. In addition, the depalmitoylase α/β-hydrolase domain-containing 16A (ABHD16A) negatively regulates the anti-HBV activity of IFITM1. Overall, our findings provided ABHD16A as a potential target for interfering with HBV replication.

HBV sequence integrated to enhancer acting as oncogenic driver epigenetically promotes hepatocellular carcinoma development

BACKGROUND

HBV integration is considered as the main contributor to hepatocellular carcinoma (HCC). However, whether HBV integrated sequences determine genotype pathogenicity and how to block their function during HCC progression remains unclear.

METHODS

An in vitro HBV-infected PHH model and liver cancer cell lines were established to confirm the pathogenic potential of HBV-SITEs. The roles of HBV-SITE-1 in HCC development were analyzed using cellular phenotypic assays and molecular biology techniques, including the combined analysis of RNA-seq and ChIP-seq. Animal models were also used to evaluate the therapeutic effect of HBV-miR-2 inhibitors.

RESULTS

We identified nine fragments of HBV Sequences Integrated To Enhancer, termed as "HBV-SITEs". Particularly, a single nucleotide variation (T > G) was embedded at seed sequence of HBV-miR-2 in the highest integrated HBV-SITE-1 between genotypes B and H. Unexpectedly, B-HBV-SITE-1, not H-HBV-SITE-1, could abnormally activate oncogenic genes including TERT and accelerate HCC cell proliferation and migration. Meanwhile, HBV-miR-2 was gradually increased in HBV-infected cells and patient plasma with different HCC stages. Importantly, 227 genes upregulated by HBV, were also activated by HBV-miR-2 through triggering HBV-SITE-1 enhancer. Conversely, enhancer activities were particularly decreased by HBV-miR-2 inhibitors, and further downregulated activated oncogenic genes. Finally, HCC growth was dramatically restrained and HBV-induced transcripts were systematically reduced via injection of HBV-miR-2 inhibitors in animal models.

CONCLUSION

HBV-SITEs were identified as novel oncogenic elements for HCC, which provides an insightful perspective for the other cancers caused by oncogenic DNA viruses. We demonstrated that the integrated HBV sequence itself acted as oncogenic enhancers and nucleotide variations of HBV genotypes account for particular pathogenic progression, supporting that the viral nucleotide sequences are vital pathogenic substances beyond viral proteins. And modulation of their enhancer activities could be clinically achievable strategy for blocking DNA viruses-related cancer progression in the future.

Ubiquitin-dependent proteasomal degradation of small hepatitis B virus surface antigen mediated by TRIM21 and antagonized by OTUD4

The small hepatitis B surface antigen (SHBs) is the most abundant hepatitis B virus (HBV) protein in individuals infected with HBV, and clearance of HBV surface antigen, which is primarily composed of SHBs, is considered a surrogate biomarker for achieving a functional cure of chronic HBV. Understanding SHBs degradation is crucial for its elimination and targeted eradication strategies. This study demonstrates that SHBs undergoes degradation via a ubiquitin/proteasome pathway, primarily through K48-linked ubiquitination, with K122 as the critical ubiquitination site. Utilizing immunoprecipitation and mass spectrometry, we identified TRIM21 (an E3 ubiquitin ligase) and OTUD4 (a deubiquitinase) as key regulators of SHBs. We verified the direct interaction between SHBs and TRIM21's coiled-coil domain, as well as the N-terminal amino acids 1-180 of OTUD4, using coimmunoprecipitation and glutathione S-transferase (GST) pull-down assays in both in vivo and in vitro settings. TRIM21 was observed to reduce SHBs stability and abundance by promoting its polyubiquitination, whereas OTUD4 acted to negate the effects of TRIM21-induced polyubiquitination, thereby stabilizing and increasing the levels of SHBs. Notably, TRIM21-mediated degradation of SHBs substantially impaired subviral particle and virion production and its biological activities such as migratory and angiogenic capabilities, opposite to the effect produced by the introduction of OTUD4. These findings suggest that TRIM21 and OTUD4 modulate SHBs protein stability and function through a ubiquitination-dependent proteasomal pathway, offering new insights into clearing SHBs and intervening in the progression of HBV-related liver diseases.IMPORTANCEThe small hepatitis B surface antigen (SHBs) is a key structural component of the hepatitis B virus (HBV) virion and subviral particles and is the most abundant HBV protein in individuals with chronic infection. Gaining a better understanding of its degradation pathways may help inform strategies to reduce SHBs levels and potentially support the design of targeted therapies. However, the specific mechanisms and processes involved in the degradation of SHBs remain largely unexplored. This study reveals that SHBs is degraded via the ubiquitin/proteasome pathway, specifically through K48-linked ubiquitination at the K122 site. TRIM21 promotes SHBs degradation by enhancing its polyubiquitination, while OTUD4 stabilizes SHBs by counteracting TRIM21's effects. TRIM21 reduces SHBs stability, subviral particle and virion production, and its related biological activities, whereas OTUD4 stabilizes SHBs, promoting its accumulation. These findings highlight the roles of TRIM21 and OTUD4 in regulating SHBs stability and function, offering new insights into potential interventions for HBV-related liver diseases.

Exploiting Host Kinases to Combat Dengue Virus Infection and Disease

The burden of dengue on human health has dramatically increased in recent years, underscoring the urgent need for effective therapeutic interventions. Despite decades of research since the discovery of the dengue virus, no specific antiviral treatments are available and strategies to reliably prevent severe disease remain limited. Direct-acting antivirals against dengue are under active investigation but have shown limited efficacy to date. An underappreciated Achille's heal of the virus is its dependence on host factors for infection and pathogenesis, each of which presents a potential avenue for therapeutic intervention. We and others have demonstrated that dengue virus relies on multiple host kinases, some of which are already targeted by clinically approved inhibitors. These offer drug repurposing opportunities for host-directed dengue treatment. Here, we summarize findings on the role of kinases in dengue infection and disease and highlight potential kinase targets for the development of innovative host-directed therapeutics.

Design and biochemical evaluation of 2-cyclopropyl-thioureidobenzamide (CP-TBA) derivatives as potent HBV capsid assembly modulators targeting a novel binding site

Hepatitis B virus (HBV) capsid assembly modulators (CAMs) represent a promising therapeutic approach in the treatment of chronic HBV infection. In the quest for effective therapeutics against chronic Hepatitis B virus (HBV) infection, we employed a novel binding site occupancy strategy to develop novel 2-cyclopropyl-thioureidobenzamide (CP-TBA) derivatives as potent HBV CAMs. Our diversity modification approach led to the identification of compound 17e, which demonstrated remarkable anti-HBV activity with an EC50 of 0.033 μM in HepAD38 cells. Molecular insights obtained through docking and dynamics simulations have provided a comprehensive understanding of the hydrogen bonding interactions between 17e and crucial residues of the HBV core protein, while also revealing the occupation of a novel binding site by the cyclopropyl group, thereby elucidating its inhibitory mechanism. Although 17e exhibited robust metabolic stability in plasma, it underwent rapid metabolism in human liver microsomes. This study underscores the potential of CP-TBA derivatives in crafting the next generation of HBV CAMs with enhanced activity and druggability.

Impact of hepatitis B surface antigen quantification on achieving a functional cure in patients with chronic hepatitis B: A systematic review and meta-analysis

INTRODUCTION AND OBJECTIVES

Baseline hepatitis B surface antigen (HBsAg) levels are associated with the likelihood of achieving HBsAg loss which defines the functional cure. However, optimal HBsAg cut-offs for predicting HBsAg loss have not been systematically investigated." Therefore, in this systematic review and meta-analysis, we evaluated the impact of baseline levels of HBsAg on achieving a functional cure in patients with chronic hepatitis B (CHB).

MATERIALS AND METHODS

We searched PubMed, Embase, and Cochrane Library up to December 31, 2023, to identify studies comparing combination therapy with nucleos(t)ide analogues (NAs) and conventional/pegylated interferon (IFN) versus monotherapy. We pooled the proportion of HBsAg loss among studies stratified by different 75th percentile of baseline HBsAg levels and other clinical characteristics.

RESULTS

We included 24 studies with 3446 participants. At the end of treatment, studies recruiting patients with 75th percentile of baseline HBsAg below 500 and 1000 IU/mL had the highest proportions of HBsAg loss in the combination group, reaching 14 % (95 % CI: 9-21 %) and 17 % (95 % CI: 10-24 %), respectively. One-year IFN-NAs combination treatment achieved a higher proportion of HBsAg loss (9 %, 95 % CI: 6-12 %) than six-month IFN-NAs treatment (1 %, 95 % CI: 0-2 %). Patients with normal alanine transaminase (ALT) had higher HBsAg loss (11 %, 95 % CI: 6-17 %) than those with elevated ALT (4 %, 95 % CI: 2-7 %). Meta-regression indicated a positive association between male percentage in studies and HBsAg loss.

CONCLUSIONS

The optimal baseline HBsAg thresholds would be 500-1000 IU/mL, which represents high-response subpopulation for achieving functional cure with currently available therapy.

Predicting relapse after achieving a functional cure for chronic hepatitis B (CHB) using baseline HBsAg and end-of-treatment HBsAb levels

Among the factors influencing relapse after clinical cure of chronic hepatitis B(CHB). There is no standardization of baseline HBsAg levels and end-of-treatment HBsAb levels. This multicenter, retrospective study enrolled 136 patients who achieved functional cure from June 2019 to December 2023, and a total of 48 weeks of follow-up was conducted after treatment cessation according to the CHB guidelines. Baseline characteristics of patients were analyzed using univariates. Multifactorial logistic regression was used to analyze the different levels of HBsAg at baseline and HBsAb at the end of treatment in CHB recurrence. The working characteristic curve of the subject was constructed and observed by the column line graphical prediction model. Our data showed the cumulative recurrence rate using Kaplan-Meier survival analysis. At baseline, the level of HBsAg was significantly greater in the group with recurrence than in the group without recurrence (P = 0.038). At EOT, HBsAb levels were lower in the relapsed group than in the nonrelapsed group (P = 0.014). Multivariate logistic regression analysis revealed that a baseline serum HBsAg concentration ≥ 100 IU/mL was a risk factor for recurrence, and an EOT serum HBsAb concentration ≥ 500 mIU/mL was a protective factor for recurrence. Kaplan-Meier survival analysis showed relapse rates of 3.8% and 12.2% for HBsAg ≤ 100 IU/mL at baseline and HBsAb ≥ 500 mIU/mL at the end of treatment, respectively. Functionally cured patients with CHB when baseline HBsAg ≤ 100 IU/mL and HBsAb ≥ 500 mIU/mL at the end of treatment have a low relapse rate.

Halting hepatocellular carcinoma: Identifying intercellular crosstalk in HBV-driven disease

Hepatitis B infection can lead to liver fibrosis and hepatocellular carcinoma (HCC). Despite antiviral therapies, some patients still develop HCC. This study investigates hepatitis B virus (HBV)-induced hepatocyte-hepatic stellate cell (HSC) crosstalk and its role in liver fibrosis and HCC. Using MYC-driven liver cancer stem cell organoids, HCC-patient-derived xenograft (PDX) models, and HBV replication models, this study reveals that HBV transcription affected hepatocyte development, activated the DNA repair pathway, and promoted glycolysis. HBV activated nicotinamide phosphoribosyltransferase (NAMPT) through DNA damage receptor ATR. NAMPT-insulin receptor (INSR)-mediated hepatocyte-HSC crosstalk caused HSCs to develop a myofibroblast phenotype and activated telomere maintenance mechanisms via PARP1 multisite lactylation. Inhibition of the ATR-NAMPT-INSR-PARP1 pathway effectively blocks HBV-induced liver fibrosis and HCC progression. Targeting this pathway could be a promising strategy for chronic HBV infection management.

Predictive value of soluble PD-1 for HBsAg loss in HbeAg-negative patients with chronic hepatitis B: results from a prospective study

BACKGROUND

Soluble PD-1 (sPD-1) has emerged as a potential biomarker in chronic hepatitis B (CHB), but its predictive value for treatment response remains unclear.

OBJECTIVE

To examine the relationship between sPD-1 dynamics and HBsAg loss in HBeAg-negative CHB patients undergoing IFN-based therapy and assess the potential of sPD-1 as a biomarker for treatment response.

METHODS

We enrolled 222 HBeAg-negative CHB patients from a prospective study. Patients received at least 48 weeks of PEG-IFNα-2b therapy and were grouped based on HBsAg status at week 48 (loss vs. persistence). Peripheral blood sPD-1 levels were measured by ELISA, and PD-1 expression on CD4+ and CD8+ T cells was analyzed by flow cytometry. Propensity score matching (PSM) and Cox regression were applied to identify predictors of HBsAg loss.

RESULTS

Among the patients, 38.7% (86/222) achieved HBsAg loss. After PSM, both the HBsAg loss and HBsAg persistence groups included 74 patients, respectively. A reduction in HBsAg of more than 70% at week 12 (p = 0.012) and baseline sPD-1 level lower than 100 pg/mL (p = 0.016) were identified as independent predictors of HBsAg loss. sPD-1 levels showed a positive correlation with HBsAg levels, whereas PD-1 expression on peripheral CD4+ and CD8+ T cells demonstrated no significant association with HBsAg levels, suggesting that sPD-1 may better reflect systemic immune status.

CONCLUSIONS

sPD-1 may serve as a potential biomarker for predicting HBsAg loss in HBeAg-negative CHB patients undergoing IFN-based therapy.

Functional Cure for Hepatitis B Virus: Challenges and Achievements

The Hepatitis B Virus (HBV) presents a formidable global health challenge, impacting hundreds of millions worldwide and imposing a considerable burden on healthcare systems. The elusive nature of the virus, with its ability to establish chronic infection and evade immune detection, and the absence of curative agents have prompted efforts to develop novel therapeutic approaches beyond current antiviral treatments. This review addresses the challenging concept of a functional cure for HBV, a state characterized by the suppression of HBV and HBsAg, mitigating disease progression and transmission without a complete cure. We provide an overview of HBV epidemiology and its clinical impact, followed by an exploration of the current treatment landscape and its limitations. The immunological basis of a functional cure is then discussed, exploring the intricate interplay between the virus and the host immune response. Emerging therapeutic approaches, such as RNA interference-based interventions, entry inhibitors, nucleic acid polymers, and therapeutic vaccines, are discussed with regard to their success in achieving a functional cure. Lastly, the review underscores the urgent need for innovative strategies to achieve a functional cure for HBV.

The Intrinsically Disordered Region of HBx and Virus-Host Interactions: Uncovering New Therapeutic Approaches for HBV and Cancer

Human viral infections remain a significant global health challenge, contributing to a substantial number of cancer cases worldwide. Among them, infections with oncoviruses such as hepatitis B virus (HBV) and hepatitis C virus (HCV) are key drivers of hepatocellular carcinoma (HCC). Despite the availability of an effective HBV vaccine since the 1980s, millions remain chronically infected due to the persistence of covalently closed circular DNA (cccDNA) as a reservoir in hepatocytes. Current antiviral therapies, including nucleos(t)ide analogs and interferon, effectively suppress viral replication but fail to eliminate cccDNA, underscoring the urgent need for innovative therapeutic strategies. Direct-acting antiviral agents (DAAs), which have revolutionized HCV treatment with high cure rates, offer a promising model for HBV therapy. A particularly attractive target is the intrinsically disordered region (IDR) of the HBx protein, which regulates cccDNA transcription, viral replication, and oncogenesis by interacting with key host proteins. DAAs targeting these interactions could inhibit viral persistence, suppress oncogenic signaling, and overcome treatment resistance. This review highlights the potential of HBx-directed DAAs to complement existing therapies, offering renewed hope for a functional HBV cure and reduced cancer risk.

Myricetin supresses HBV replication both in vitro and in vivo via inhibition of HBV promoter SP2

Hepatitis B virus (HBV) infection remains a significant global public health concern. Myricetin, a flavonoid compound widely distributed in natural plants, has demonstrated multiple biological functions in combating diseases such as cancer and inflammation. In this research, we explored the mechanism of myricetin against HBV replication. We employed various experiments such as ELISA, Southern Blot, Northern Blot, Western Blot, RT-qPCR, Dual luciferase reporter gene assay, ChIP, EMSA, IHC, Immunofluorescence, AAV infection, and isolation of primary human hepatocytes (PHH) in this study. Our results showed that myricetin significantly reduced the expression of HBV markers, including HBsAg, HBeAg and covalently closed circular DNA (cccDNA), in HepG2-NTCP cells and PHH. We further confirmed these findings using AAV-HBV cell and mouse models. Furthermore, we found that myricetin significantly downregulated HBV SP2 promoter activity. Mechanistically, myricetin reduced CEBPA expression, which in turn interfered with the binding of CEBPA to the HBV SP2 promoter, leading to an antiviral effect. In conclusion, myricetin exhibited promising antiviral activity against HBV, suggesting its potential for novel HBV treatment.

Incidence and Predictors of HBsAg Loss in Paediatric Patients With Chronic Hepatitis B Undergoing Antiviral Treatment

BACKGROUND AND AIMS

Achieving HBsAg loss is a critical clinical milestone in the management of chronic hepatitis B (CHB) towards the eradication of hepatitis B. However, there are limited researches on the incidence and determinants of HBsAg loss in paediatric CHB patients undergoing antiviral treatment. Therefore, we aimed to analyse the incidence and potential determinants of HBsAg loss in children who suffered from CHB and received antiviral treatment.

METHODS

This retrospective cohort study was performed on paediatric patients with progressive CHB who initiated either monotherapy or combination therapy using interferon/peg-interferon and entecavir. We utilised Cox regression models to evaluate the relationships between HBsAg loss and various determining factors.

RESULTS

In total of 306 subjects with an average age of 4.99 years (range 1-15) were identified in this study, of whom 200 (65.4%) were male. After a median follow-up of 26 months, HBsAg loss occurred in 135 participants. The accumulated rate of HBsAg loss was 67.8% at the end of the follow-up evaluation. Multivariate Cox regression analysis revealed that older age (HR = 0.84, 95% CI: 0.79-0.90), female sex (HR = 1.61, 95% CI: 1.13-2.30), baseline HBsAg levels (HR = 0.72, 95% CI: 0.62-0.84), HBsAb positivity (HR = 1.77, 95% CI: 1.20-2.59) and serum bilirubin levels (HR = 0.96, 95% CI: 0.92-0.99) were statistically significant predictors of HBsAg loss.

CONCLUSION

The incidence of HBsAg loss continues to increase in paediatric patients with CHB after antiviral treatment. Age, sex, baseline HBsAg and bilirubin levels and HBsAb positivity are found to be associated with sustained HBsAg loss.

Nucleos(t)ide analogs continuation is not associated with a lower risk of HBsAg seroreversion following PEG-IFN-induced HBsAg loss

BACKGROUND/AIMS

It is unclear whether nucleos(t)ide analogs (NUCs) continuation provides clinical benefits following HBsAg seroclearance with pegylated interferon (PEG-IFN)-based therapy. This study aims to investigate the role of NUCs continuation in HBsAg seroreversion.

METHODS

Patients who experienced serum HBsAg loss after PEG-IFN-based therapy were enrolled and followed up for 96 weeks. Propensity score matching (PSM) was performed using a 1:1 ratio to adjust for the associated factors. A multivariate logistic regression analysis was used to determine the factors associated with HBsAg seroreversion.

RESULTS

In total, 220 patients with HBsAg seroclearance were divided into NUCs (n = 54) and non-NUCs (n = 166) consolidation therapy groups. At week 96, the HBsAg seroreversion (12/54 vs. 31/166, P = 0.709) and virological relapse (2/54 vs. 10/166, P = 0.759) rates were similar in the NUCs and non-NUCs groups. After PSM, HBsAg seroreversion (12/53 vs. 13/53; P = 1.000) and virological relapse (2/53 vs. 4/53; P = 0.674) rates were not significantly different between the two groups. Serum hepatitis B surface antibody titer (odds ratio, 0.388; 95% confidence interval, 0.245-0.616; P < 0.001) was found to be associated with HBsAg seroreversion, while NUCs continuation was not related to HBsAg seroreversion.

CONCLUSIONS

NUCs continuation is not associated with a lower risk of HBsAg seroreversion in patients with serum HBsAg loss following PEG-IFN-based therapy.

Altered LY6E and TRIM6 expression in PBMCs correlated with HBsAg clearance and response to Peg-IFN-α treatment in HBeAg-negative chronic hepatitis B patients

BACKGROUND

Pegylated interferon alpha (Peg-IFN-α) has the potential to eradicate hepatitis B surface antigen (HBsAg). This study aimed to investigate whether the expression levels of lymphocyte antigen 6 family member E (LY6E) and tripartite motif-containing protein 6 (TRIM6) mRNAs in peripheral blood mononuclear cells (PBMCs) of hepatitis B e antigen (HBeAg)-negative chronic hepatitis B virus (HBV) patients is associated with the response to Peg-IFN-α treatment and HBsAg clearance.

METHODS

In this prospective study, HBeAg-negative chronic HBV patients treated with Peg-IFN-α were followed for 48 weeks. The participants were classified into two groups, the virological response (VR) group and nonvirological response (NVR) group, according to the changes in HBV DNA and HBsAg levels observed at week 48 of treatment. Furthermore, these patients were divided into a serological response (SR) group and a nonserological response (NSR) group, depending on whether they exhibited a loss of serum HBsAg or evidence of seroconversion. The expression levels of LY6E and TRIM6 mRNAs in PBMCs were evaluated using real-time quantitative PCR with fluorescence detection. The diagnostic performance of LY6E and TRIM6 was assessed by analyzing the receiver operating characteristic (ROC) curve and calculating the area under the ROC curve (AUC).

RESULTS

After the treatment period, the observed VR and SR rates were 44.64% and 28.57%, respectively. Dynamic changes in LY6E and TRIM6 mRNA levels were significantly different between the VR and NVR groups and between the SR and NSR groups. Multivariate analysis revealed that TRIM6 was independently associated with VR at weeks 12 and 24 of Peg-IFN-α therapy and with SR at week 12; in addition, LY6E was independently associated with VR at week 12 and SR at week 24. At week 24, the area under the curve (AUC) for LY6E in the prediction of VR was 0.6942, and the AUC for the prediction of SR was 0.7766; at week 12, TRIM6 had AUCs of 0.7600 for the prediction of VR and 0.8469 for the prediction of SR.

CONCLUSIONS

LY6E and TRIM6 are important biomarkers for early therapeutic responses to Peg-IFN-α and HBsAg clearance.

TRIAL REGISTRATION

Registration number: 2023 - 311. Date of registration: 1 October 2023.

Predictors of Functional Cure of Chronic Hepatitis B Virus Infection: A Long-Term Follow-Up Study

BACKGROUND & AIMS

A functional cure is an essential endpoint in the management of patients with chronic hepatitis B virus (HBV) infection. We evaluated the cumulative probability and predictors of functional cure in patients with chronic HBV infection after hepatitis B e antigen (HBeAg) seroconversion.

METHODS

We retrospectively analyzed 413 (249 males and 164 females) initially HBeAg-positive chronic HBV-infected patients who were followed up for a mean of 26.36 ± 0.53 years. All underwent HBeAg seroconversion during follow-up. A functional cure was defined as durable HBsAg and HBV DNA loss without antiviral treatment for more than 24 weeks.

RESULTS

After 10,888 person-years of follow-up, the cumulative probability of functional cure was 14.53% (n = 60). There were 24 (40%) subjects with functional cure after antiviral therapy. The annual functional cure rate was 0.55% per person-year, and increased to 0.96% per person-year after HBeAg seroconversion. In subjects with functional cure, the HBsAg and HBV DNA titers after HBeAg seroconversion were positively correlated with the time to functional cure (P < .001 and < .001, respectively). Multivariate Cox proportional hazards analysis of the cohort revealed that HBeAg seroconversion at <18 years of age, high-genetic-barrier nucleos(t)ide analogue(s) therapy before HBeAg seroconversion, and a serum HBsAg titer <1000 IU/mL at 18 months after HBeAg seroconversion were significant predictors of functional cure (P < .001, .001, and .001, respectively).

CONCLUSIONS

In a cohort of chronic HBV-infected patients with long-term follow-up, HBeAg seroconversion in childhood, high-genetic-barrier nucleos(t)ide analogue(s) therapy, and low HBsAg titers after HBeAg seroconversion were significant predictors of functional cure.

Alcohol-Induced Dendritic Cells and Their Exosomes Promote T-Cell Immunity in Hepatitis B Virus Transgenic Mice and Patients With Chronic Hepatitis B

Dendritic cells and the exosomes they secrete play a crucial role in the immune system, and studies have shown that dendritic cell function is dramatically reduced in patients with chronic hepatitis B. Alcohol could stimulate dendritic cell maturation. Consequently, the present work explored the therapeutic effect of alcohol-induced dendritic cells and their exosomes in hepatitis B virus (HBV) infection. We systematically investigated the functional effects of alcohol stimulation and HBV infection on dendritic cells and their exosomes, as well as cocultured alcohol-induced dendritic cells and exosomes with lymphocytes from HBV transgenic mice and chronic hepatitis B patients to study the T cell immune response. Our findings revealed that alcohol significantly accelerated the maturation of bone marrow-derived dendritic cells in mice and dendritic cells in patients with chronic hepatitis B, but had no effect on the DC2.4 cell line. Simultaneously, HBV infection was demonstrated to inhibit dendritic cell activation and maturation, as well as exosomes. More importantly, alcohol-induced dendritic cells enhanced T-cell immunity in HBV transgenic mice and chronic hepatitis B patients, and their exosomes had the same impact. The maturation of dendritic cells and their exosomes can be effectively induced by alcohol. Meanwhile, alcohol-induced maturation of dendritic cells and exosomes can significantly repair the poor T-cell immunity caused by HBV infection, making it a promising novel treatment for chronic hepatitis B patients in the future.

Peripheral Blood CD4+/CD8+ T Cell Ratio Predicts HBsAg Clearance in Inactive HBsAg Carriers Treated with Peginterferon Alpha

BACKGROUND AND AIMS

T lymphocytes play a pivotal role in resolving hepatitis B virus infection. This study aimed to investigate the dynamics of peripheral blood T lymphocyte subsets during peginterferon alpha (peg-IFN-α) therapy and their association with hepatitis B surface antigen (HBsAg) clearance in inactive HBsAg carriers (IHCs).

METHODS

This prospective observational study enrolled 197 IHCs treated with peg-IFNα-2a/2b for 48 weeks and followed for 24 weeks (treatment group), and 221 IHCs who were regularly monitored for 72 weeks without treatment (IHC control group). Peripheral blood T lymphocyte subsets were evaluated using flow cytometry at baseline, and at 12, 24, 48, and 72 weeks in both groups. At 72 weeks, IHCs in the treatment group were categorized into an HBsAg clearance group and an HBsAg persistence group. Differences in T lymphocyte subsets among these groups were compared, and correlations between T lymphocyte subsets and HBsAg clearance were analyzed.

RESULTS

At 72 weeks, intention-to-treat analysis showed significantly higher HBsAg clearance (46.7%) and seroconversion rates (34.5%) in the treatment group compared to the IHC control group (HBsAg clearance rate of 1.4%, seroconversion rate of 0.9%; both p < 0.001). The median absolute counts of CD3+, CD4+, and CD8+ cells significantly decreased at 12, 24, and 48 weeks in both the HBsAg clearance and persistence groups, returning to baseline at 72 weeks (all p < 0.001). IHCs with HBsAg clearance had higher median percentages of CD3+ CD8+ cells and lower median percentages of CD3+ CD4+ cells and CD4+/CD8+ ratios at 12, 24, and 48 weeks compared to the HBsAg persistence and IHC control groups (all p < 0.001). Baseline HBsAg levels (below 2.0 log10 IU/mL) and hepatitis B virus DNA levels (below 20 IU/mL), alanine aminotransferase elevation at 12 weeks (greater than 2×upper limit of normal), and CD4+/CD8+ ratios (less than 1.5 at 12 weeks and below 1.4 at 24 weeks) were predictive of HBsAg clearance.

CONCLUSIONS

Peripheral blood CD4+/CD8+ ratios at 12 and 24 weeks may serve as predictive markers for HBsAg clearance in IHCs treated with peg-IFN-α.

Targeting hepatitis B virus-associated nephropathy: efficacy and challenges of current antiviral treatments

Hepatitis B virus (HBV) infection remains a major global health challenge, affecting approximately 296 million people and causing significant mortality annually. Despite vaccination efforts, HBV prevalence persists, particularly in low- and middle-income regions and endemic areas like China. HBV is closely associated with various kidney diseases, including acute kidney injury, chronic kidney disease, and glomerulonephritis, through mechanisms such as immune complex deposition, direct viral invasion, and chronic inflammation. Patients undergoing hemodialysis or kidney transplantation are at increased risk of HBV infection and reactivation, highlighting the need for effective preventive and therapeutic measures. This review examines the classification and clinical features of HBV-associated nephropathy, focusing on membranous nephropathy and membranoproliferative glomerulonephritis. It explores the pathogenesis, emphasizing immune complex deposition and podocyte apoptosis. Antiviral therapy, particularly with nucleos(t)ide analogs like entecavir and tenofovir (including TAF and TMF), demonstrates superior efficacy and safety compared to older agents such as lamivudine and adefovir. While interferon therapy offers benefits, its use is limited by adverse effects. Additionally, individualized treatment strategies for specific populations, including pregnant women and HIV co-infected patients, are crucial. Addressing HBV-associated nephropathy requires enhanced surveillance, timely antiviral intervention, and tailored therapeutic approaches to improve patient outcomes.

Molecular mechanisms in liver repair and regeneration: from physiology to therapeutics

Liver repair and regeneration are crucial physiological responses to hepatic injury and are orchestrated through intricate cellular and molecular networks. This review systematically delineates advancements in the field, emphasizing the essential roles played by diverse liver cell types. Their coordinated actions, supported by complex crosstalk within the liver microenvironment, are pivotal to enhancing regenerative outcomes. Recent molecular investigations have elucidated key signaling pathways involved in liver injury and regeneration. Viewed through the lens of metabolic reprogramming, these pathways highlight how shifts in glucose, lipid, and amino acid metabolism support the cellular functions essential for liver repair and regeneration. An analysis of regenerative variability across pathological states reveals how disease conditions influence these dynamics, guiding the development of novel therapeutic strategies and advanced techniques to enhance liver repair and regeneration. Bridging laboratory findings with practical applications, recent clinical trials highlight the potential of optimizing liver regeneration strategies. These trials offer valuable insights into the effectiveness of novel therapies and underscore significant progress in translational research. In conclusion, this review intricately links molecular insights to therapeutic frontiers, systematically charting the trajectory from fundamental physiological mechanisms to innovative clinical applications in liver repair and regeneration.

Dynamic Changes of Growth and Thyroid Function in Young Children With Chronic Hepatitis B Treated With Peginterferon Monotherapy

BACKGROUND

Peginterferon (PegIFN) has shown promising results in the treatment of chronic hepatitis B (CHB). This study aimed to evaluate the effects of PegIFN α-2b on growth and thyroid function in young children with CHB.

METHODS

A retrospective study was performed by extracting clinical data from children with CHB who received PegIFN α-2b monotherapy at the Public Health Clinical Center of Chengdu between June 2017 and December 2020. Mean, SD, independent samples t test and 1-way repeated analysis of variance were used to evaluate relevant data.

RESULTS

A total of 62 children were included in this study. Overall, significant differences were observed in the weight-for-age z score (WAZ), height-for-age z score (HAZ) and body mass index-for-age z score (BAZ) at different time points ( P < 0.001). WAZ, HAZ and BAZ were not affected by PegIFN α-2b at 24 weeks of treatment (all P > 0.05). WAZ, HAZ and BAZ at the end of treatment and 48 weeks after treatment; WAZ at 96 weeks after treatment were lower than baseline levels (all P < 0.05). No statistical differences were found in HAZ and BAZ at 96 weeks after treatment compared with baseline. Thyroid dysfunction developed in 17.7% of children during the treatment. Thyroid dysfunction was transient and had no effect on growth.

CONCLUSIONS

PegIFN α-2b has inhibitory effects on growth and can increase the incidence of thyroid dysfunction in young children with CHB. These effects are generally reversible with the cessation of therapy, although WAZ had not returned to baseline after 96 weeks of observation.

Evaluation of a next generation sequencing assay for Hepatitis B antiviral drug resistance on the oxford nanopore system

BACKGROUND

Next-generation sequencing (NGS) for Hepatitis B virus (HBV) antiviral resistance (AVR) testing is a highly sensitive diagnostic method, able to detect low-level mutant subpopulations. Our clinical virology laboratory previously transitioned from DNA hybridization (INNO-LiPA) to NGS, initially with the GS Junior System and subsequently the MiSeq. The Oxford Nanopore Technology (ONT) sequencing system was evaluated for HBV resistance testing, with regards to sequencing accuracy and turn-around time.

METHODS

We performed amplicon sequencing of the HBV polymerase gene from patient plasma and external quality assessment (EQA) samples on the MiSeq Reagent Nano Kit v2 and GridION ONT with R10.4.1 flowcells. Mutational analysis and genotyping were performed by DeepChek®Assay-HBV (version 2.0).

RESULTS

A total of 49 patient samples and 15 EQA samples were tested on both the MiSeq and ONT. There was high agreement for both patient and EQA samples between the MiSeq and ONT systems, with regards to total drug resistance mutations detected and total patient sample agreement, 68/70 (97 %) and 47/49 (96 %), respectively.

CONCLUSION

The ONT NGS platform provided accurate HBV AVR results, with improved turn-around times. Sequencing error rates at AVR codons were below 1 %.

Effect of immune checkpoint inhibitors on patients with hepatitis B virus infection

Hepatitis B virus (HBV) infection is regarded as a major health concern worldwide. In patients with chronic HBV infection, exhausted virus-specific CD8+ T cells, resulting from the activation of the programmed cell death protein 1 and programmed death ligand 1 axis, play a key role in the chronicity of infection. Functional cure for HBV, defined as the seroclearance of hepatitis B surface antigen (HBsAg), is viewed as the optimal goal of chronic HBV infection treatment because HBsAg loss is associated with a low risk of hepatocellular carcinoma and a relatively favorable prognosis. Both interferon treatment and finite antiviral therapy are associated with positive HBV outcomes. Overall, combining immune checkpoint inhibitors with nucleos(t)ide analogs appears to be a promising approach for achieving HBsAg loss, particularly in patients with low HBsAg levels.

Why and when could nucleos(t)ide analogues treatment be withdrawn?

Oral antiviral therapy to hepatitis B virus (HBV) with nucleos(t)ide analogues (NUCs) is effective in suppressing the viral load leading to improved clinical outcomes. However, functional cure of HBV, indicated by hepatitis B surface antigen (HBsAg) clearance from the serum, is rare. Although safety and adherence may represent minor issues in long-term treatment with the available NUCs, more efficacious treatments with finite treatment duration for patients with chronic hepatitis B (CHB) are currently undergoing active clinical investigation. Available data suggest that HBsAg loss can be achieved in 10% to 20% of patients after NUC discontinuation, at the cost of about 50% to 80% virological relapse and 40% to 55% retreatment with NUC. With this, NUC treatment in patients with cirrhosis should not be stopped to avoid detrimental risk of hepatic decompensation and death. Viral and immune biomarkers, which may be potentially useful in stratifying the patients at risk of relapse after stopping NUC therapy, are under investigation. In the era of personalized medicine aided by artificial intelligence tools, tight monitoring of viral kinetics and algorithmic modeling appear a promising strategy to assist in individualized decision and conclude the optimal timing of the NUC treatment discontinuation.

Chronic Hepatitis B Virus Persistence: Mechanisms and Insights

Chronic hepatitis B (CHB) virus infection can lead to severe liver diseases, including cirrhosis and hepatocellular carcinoma. The chronicity of the hepatitis B virus (HBV) occurs because of the persistence of viral covalently closed circular DNA (cccDNA) within hepatocytes. The cccDNA serves as the template for viral replication and is central to HBV, maintaining a viral reservoir within the host. Despite therapeutic advancements, eliminating cccDNA remains elusive due to its evasion of immune surveillance. This review explores the formation and maintenance of cccDNA, highlighting host factors influencing cccDNA stability and viral replication. It also discusses current treatment strategies, including interferon-based therapies and nucleoside/nucleotide analogs, which aim to suppress viral replication. Emerging therapies such as gene editing and molecular interventions hold promise for targeting cccDNA directly. Currently, research is focused on making medications that target host factors of interest to disrupt or clear the viral reservoir. However, future research should focus on innovative approaches that directly target the cccDNA minichromosome, aiming for sustained viral suppression and potentially a cure for the HBV infection.

Predictive factors for clinical cure in the treatment of HBeAg(-) chronic hepatitis B or compensated cirrhosis: a prospective observational study

Background

Sequential or combined treatment with nucleos(t)ide analogs (NAs) and pegylated interferon alpha-2b (Peg-IFN-α-2b) can improve the clinical cure rate. However, its clinical application is limited due to the adverse reactions associated with IFN.

Methods

A multi-center prospective observational study was conducted involving 59 NAs-treated chronic hepatitis B (CHB) patients who were treated with a combination therapy of NAs and Peg-IFN-α-2b for 48 weeks. Another 327 NAs-treated patients received NAs monotherapy for 48 weeks. At the end of the treatment, patients were classified into either the clinically cured group or the non-clinically cured group based on clinical efficacy. The study aimed to analyze the clinical cure rate and the predictive factors.

Results

After propensity score matching (PSM), a total of 104 patients were included in the exposure and the control groups. After 48 weeks of treatment, 13 patients in the exposed group achieved clinical cure, with a cure rate of 25%. In contrast, in the control group was 1.92%. The clinical cure rate was greater in the population with CHB or compensated cirrhosis treated with sequential or combined Peg-IFN-α-2b and NAs than in the control group (p < 0.001). Patients treated with Peg-IFN-α-2b were divided into a clinical cure group and a non-clinical cure group for single-factor regression and multi-factor binary logistic regression. The results showed that baseline qHBsAg [relative ratio (RR) = 0.997, 95%CI: [0.995, 0.999], p = 0.031] and △TBiL (RR = 0.698, 95%CI: [0.555, 0.879], p = 0.002) were independent influencing factors for achieving clinical cure in patients with CHB or compensated cirrhosis.

Conclusion

A lower baseline qHBsAg and decrease in TBiL at 24 weeks of treatment are independent influencing factors for achieving clinical cure. The lower the baseline qHBsAg and the higher the △TBiL levels after 24 weeks of treatment, the higher the probability of patients achieving clinical cure.

Efficacy and safety of interferon-alpha 1b injection into the intervertebral foramen with ultrasonic guidance in patients with postherpetic neuralgia: study protocol for a randomized, double-blind, placebo-controlled, multicenter clinical trial

Purpose

Postherpetic neuralgia (PHN) is a type of refractory neuropathic pain that causes significant suffering, disability, economic loss, and medical burden. In this study, we aim to evaluate the efficacy and safety of interferon (IFN)-α1b injection into the intervertebral foramen of patients with PHN.

Patients and methods

This is a study protocol for a randomized, double-blind placebo-controlled multicenter clinical trial. A total of 200 participants with PHN from 11 hospitals will be recruited and randomly assigned to the treatment group administered with IFN-α1b and control group treated with placebo in a 1:1 ratio. Both groups will also receive oral pregabalin 150 mg twice daily and lidocaine injection into the intervertebral foramen as conventional therapy. This trial will involve a screening period, a 2-week intervention, and a 3-month follow-up. The primary outcomes will include the visual analog scale score and duration of pain relief. The secondary outcomes will include the 36-item short-form, dosage and duration of painkillers taken, viral load of varicella-zoster virus DNA, humoral cytokine level, and dosage and frequency of rescue medication. All adverse events and severe adverse events will be assessed during the study.

Conclusion

This study is expected to provide evidence for the efficacy and safety of IFN-α1b injection into the intervertebral foramen in patients with PHN.

Clinical trial registration

https://www.chictr.org.cn/indexEN.html, identifier ChiCTR240008996.

HBV cccDNA: The Molecular Reservoir of Hepatitis B Persistence and Challenges to Achieve Viral Eradication

Hepatitis B virus (HBV) is a major global health issue, with an estimated 254 million people living with chronic HBV infection worldwide as of 2022. Chronic HBV infection is the leading cause of cirrhosis and liver cancer. Current treatment with nucleos(t)ide analogs is effective in the suppression of viral activity but generally requires lifelong treatment. They fail to eradicate the HBV viral reservoir, called covalently closed circular DNA (cccDNA), which replicates in the nucleus of liver cells. The cccDNA serves as the sole template for viral replication, as it generates the pregenomic RNA (pgRNA) necessary for producing new viral genomes. This stable form of viral DNA can reactivate the virus when treatment is stopped. HBV cccDNA is therefore one of the main challenges in curing chronic HBV infections. By targeting steps such as cccDNA formation, capsid assembly, or particle secretion, researchers continue to seek ways to interfere with HBV replication and to reduce its persistence, ultimately to eradicate HBV as a global health problem. This review provides an overview of what is currently known about cccDNA formation and biogenesis and the ongoing efforts to target and eradicate it to cure chronic HBV infections.

Multiomics Analyses Reveal that Fatty Acid Metabolism and TCA Cycle Contribute to the Achievement of Functional Cure in Chronic Hepatitis B

Peg-IFNα is one of the current therapeutic strategies for Hepatitis B virus (HBV) seroclearance. Nevertheless, the underlying mechanisms are not yet adequately understood. The objective of this study was to explore the potential mechanisms using multiomics approach. For the first time, we revealed the transcriptomic, proteomic, and metabolomic characterizations of Peg-IFNα-induced HBsAg seroclearance. We found that Peg-IFNα caused significant changes during the treatment. Patients who achieved HBsAg seroclearance were characterized as having decreased transcriptional activity of genes involved in fatty acid metabolism and the glycolysis/gluconeogenesis pathway, with up-regulated expression of fatty acid degradation-related proteins. Consistently, mitochondrial TCA cycle metabolites, including citric, isocitric, and malic acids, were significantly elevated in patients who achieved HBsAg seroclearance. We also observed up-regulated transcriptional activity of NK cell-mediated cytotoxicity, positive regulation of B cell activation, immunoglobulin production, and T cell receptor complex in functional-cured patients. Conversely, the metabolites associated with unsaturated fatty acid biosynthesis were increased in HBsAg persistent patients, and the transcriptional activity of immunoglobulin production and T cell receptor complex was down-regulated after 48 weeks of Peg-IFNα treatment. Our findings provided valuable resources to better understand the process of HBsAg seroclearance and shed new light on the pathways to facilitate higher functional cure rates for CHB.

Antiviral therapy for chronic hepatitis B with mildly elevated aminotransferase: A rollover study from the TORCH-B trial

BACKGROUND/AIMS

Treatment indications for patients with chronic hepatitis B (CHB) remain contentious, particularly for patients with mild alanine aminotransferase (ALT) elevation. We aimed to evaluate treatment effects in this patient population.

METHODS

This rollover study extended a placebo-controlled trial that enrolled non-cirrhotic patients with CHB and ALT levels below two times the upper limit of normal. Following 3 years of randomized intervention with either tenofovir disoproxil fumarate (TDF) or placebo, participants were rolled over to open-label TDF for 3 years. Liver biopsies were performed before and after the treatment to evaluate histopathological changes. Virological, biochemical, and serological outcomes were also assessed (NCT02463019).

RESULTS

Of 146 enrolled patients (median age 47 years, 80.8% male), 123 completed the study with paired biopsies. Overall, the Ishak fibrosis score decreased in 74 (60.2%), remained unchanged in 32 (26.0%), and increased in 17 (13.8%) patients (p<0.0001). The Knodell necroinflammation score decreased in 58 (47.2%), remained unchanged in 29 (23.6%), and increased in 36 (29.3%) patients (p=0.0038). The proportion of patients with an Ishak score ≥ 3 significantly decreased from 26.8% (n=33) to 9.8% (n=12) (p=0.0002). Histological improvements were more pronounced in patients switching from placebo. Virological and biochemical outcomes also improved in placebo switchers and remained stable in patients who continued TDF. However, serum HBsAg levels did not change and no patient cleared HBsAg.

CONCLUSION

In CHB patients with minimally raised ALT, favorable histopathological, biochemical, and virological outcomes were observed following 3-year TDF treatment, for both treatment-naïve patients and those already on therapy.

Safety, pharmacokinetics, and antiviral efficacy of the novel capsid assembly modulator GST-HG141 in patients with chronic hepatitis B: a phase 1 trial with a randomized, placebo-controlled design

In preclinical studies, GST-HG141, a novel hepatitis B virus (HBV) capsid assembly modulator displayed potent anti-HBV activity in vitro and strong efficacy in HBV animal models. A randomized, double-blind, ascending phase 1b trial assessed the pharmacokinetics, safety, and efficacy of GST-HG141 in chronic hepatitis B (CHB) individuals. Thirty treatment-naïve CHB patients were enrolled in three cohorts (25, 50, and 100 mg twice orally after meals daily) over 28 days, with 10 subjects per cohort (8:2 ratio for GST-HG141 and placebo). Dose-related safety and tolerability, pharmacokinetic profiles, and drug responses were evaluated. GST-HG141 exhibited a generally favorable safety profile across all doses with predominantly mild adverse reactions, including three cases of grade 1 transaminase elevations. Significant reductions in HBV DNA and pregenomic RNA (pgRNA) levels were observed across all doses of (25, 50, and 100 mg of GST-HG141, twice-daily) after 28 days of treatment. Pharmacokinetic analysis showed a consistent linear trend in GST-HG141 concentrations, with mean trough concentrations ranging from 75 to 240 ng/mL. These concentrations adequately covered the protein binding-adjusted EC50 (16.89 ng/mL) by factors of 4.4, 11.1, and 14.6 for doses of 25, 50, and 100 mg, respectively. Our study demonstrated GST-HG141's well-tolerated profile up to 100 mg over 4 weeks, alongside robust antiviral activity in CHB patients, supporting its progression into further clinical investigation for CHB management.

Targeting HBV cccDNA Levels: Key to Achieving Complete Cure of Chronic Hepatitis B

Chronic hepatitis B (CHB) caused by HBV infection has brought suffering to numerous people. Due to the stable existence of HBV cccDNA, the original template for HBV replication, chronic hepatitis B (CHB) is difficult to cure completely. Despite current antiviral strategies being able to effectively limit the progression of CHB, complete CHB cure requires directly targeting HBV cccDNA. In this review, we discuss strategies that may achieve a complete cure of CHB, including inhibition of cccDNA de novo synthesis, targeting cccDNA degradation through host factors and small molecules, CRISP-Cas9-based cccDNA editing, and silencing cccDNA epigenetically.

Augmented epigenetic repression of hepatitis B virus covalently closed circular DNA by interferon-α and small-interfering RNA synergy

The persistence of hepatitis B virus (HBV) covalently closed circular DNA (cccDNA) is a key obstacle for HBV cure. This study aims to comprehensively assess the effect of interferon (IFN) and small-interfering RNA (siRNA) combination on the cccDNA minichromosome. Utilizing both cell and mouse cccDNA models, we compared the inhibitory effects of IFNα, siRNA, and their combination on cccDNA activity and assessed its epigenetic state. IFNα2 treatment alone reduced HBV RNAs, HBeAg, and HBsAg levels by approximately 50%, accompanied by a low-level reconstitution of SMC5/6-a chromatin modulator that restricts cccDNA transcription. HBx-targeting siRNA (siHBx) achieved significant suppression of viral antigens and reconstitution of SMC5/6, but this effect could be reversed by the deacetylase inhibitor Belinostat. The combination of IFN with siHBx resulted in over 95% suppression of virological markers, reduction in epigenetic activation modifications (H3Ac and H4Ac) on cccDNA, and further reduced cccDNA accessibility, with the effect not reversible by Belinostat. In an extracellular humanized IFNAR C57BL/6 mouse model harboring recombinant cccDNA, the effect of combination of clinically used pegylated IFNα2 and GalNac-siHBx was further clarified, indicating a higher and more durable suppression of cccDNA activity compared to either therapy alone. In conclusion, the combination of IFNα and siRNA achieves a more potent and durable epigenetic inhibition of cccDNA activity in cell and mouse models, compared to monotherapy. These findings deepen the understanding of cccDNA modulation and strengthen the scientific basis for the potential of combination therapy.

IMPORTANCE

Since there are currently no approved drugs targeting and silencing covalently closed circular DNA (cccDNA), achieving a "functional cure" remains difficult. This study aims to comprehensively compare the effects of IFNα, small-interfering RNA targeting hepatitis B virus (HBV), and their combination on the activity, accessibility, and epigenetic modifications of cccDNA minichromosomes in cell models. A more durable and stable inhibition of HBV RNAs and antigens expression by IFNα and HBx-targeting siRNA (siHBx) synergy was observed, associated with augmented epigenetic repression of the cccDNA minichromosome. Besides, in an extracellular humanized IFNAR mouse model harboring recombinant cccDNA with an intact response to human IFNα, the synergistic effect of clinically used pegylated IFNα2 and in-house-developed GalNac-siHBx was further clarified.

Chronic Hepatitis B Genotype C Mouse Model with Persistent Covalently Closed Circular DNA

Hepatitis B virus (HBV) can cause chronic infections, significantly increasing the risk of death from cirrhosis and hepatocellular carcinoma (HCC). A key player in chronic HBV infection is covalently closed circular DNA (cccDNA), a stable episomal form of viral DNA that acts as a persistent reservoir in infected hepatocytes and drives continuous viral replication. Despite the development of several animal models, few adequately replicate cccDNA formation and maintenance, limiting our understanding of its dynamics and the evaluation of potential therapeutic interventions targeting cccDNA. In this study, we aimed to develop a mouse model to investigate cccDNA formation and maintenance. We infected C57BL/6 mice with recombinant adeno-associated virus (rAAV) carrying a 1.3-overlength HBV genome (genotype C) and collected liver tissue at various time points to assess cccDNA levels and viral replication. Our results demonstrated the successful establishment of a chronic hepatitis B mouse model using rAAV-HBV1.3, which supported persistent HBV infection with sustained cccDNA expression in hepatocytes. Serum levels of HBsAg and HBeAg were elevated for up to 12 weeks, while alanine transaminase (ALT) levels remained within the normal range, indicating limited liver damage during this period. We confirmed HBV DNA expression in hepatocytes, and importantly, cccDNA was detected using qPCR after Plasmid-Safe ATP-Dependent DNase treatment, which selectively removes non-cccDNA forms. Additionally, Southern blot analysis confirmed the presence of cccDNA isolated using the Hirt extraction method. This established model provides a valuable platform for studying the long-term maintenance of cccDNA in chronic HBV infection and offers an important tool for testing novel therapeutic strategies aimed at targeting cccDNA.

Virological and serological outcomes in people with HIV-HBV coinfection who had discontinued tenofovir-containing antiretroviral therapy: Results from a prospective cohort study

Background and Aims

Given advances in antiretroviral therapy (ART), some people with HIV are transitioned to non-tenofovir-containing ART; the implications for people with HIV-hepatitis B virus (HBV) are unknown. We characterized HBV-related outcomes in people with HIV-HBV coinfection while not taking tenofovir-containing ART.

Methods

We analyzed participants from the French HIV-HBV Cohort Study in three treatment groups: (1) continuous tenofovir; (2) discontinued tenofovir; (3) never initiated tenofovir. We examined virological and clinical characteristics during follow-up. We assessed determinants of HBV DNA >2000 IU/mL and alanine aminotransferase (ALT) >2x upper limit of normal separately while participants were off tenofovir using univariable logistic regression with generalized estimating equations.

Results

Among 192 participants, 161 (83.9 %) were on continuous tenofovir, 22 (11.5 %) discontinued tenofovir, and 9 (4.7 %) never initiated tenofovir during a median follow-up of 14.5 years (IQR = 10.5-14.8). The median proportion of within-participant visits with undetectable HBV DNA was 96.0 % (IQR = 75.0-100) in the continuous group, 100 % (IQR = 84.0-100) in the discontinued tenofovir group (while off tenofovir), and 100 % (IQR = 95.2-100) in the never initiated tenofovir group. Determinants of HBV DNA >2000 IU/mL while people were off tenofovir were detectable HIV RNA (p = 0.041), lower CD4+ T-cell count (p = 0.027), HBeAg positive serology (p = 0.004) and positive hepatitis D serology (p = 0.001). ALT elevation was associated with positive hepatitis C antibody serology (p = 0.012).

Conclusions

This proof-of-concept study shows that selected people with HIV-HBV coinfection may not lose virologic control of HBV when off tenofovir. HBV virologic activity while off tenofovir may be more closely associated with uncontrolled HIV infection and positive HBeAg serology.

Epigenetic modification of hepatitis B virus infection and related hepatocellular carcinoma

Hepatitis B virus (HBV) infection poses a challenge to global public health. Persistent liver infection with HBV is associated with an increased risk of developing severe liver disease. The complex interaction between the virus and the host is the reason for the persistent presence of HBV and the risk of tumor development. Chronic liver inflammation, integration of viral genome with host genome, expression of HBx protein, and viral genotype are all key participants in the pathogenesis of hepatocellular carcinoma (HCC). Epigenetic regulation in HBV-associated HCC involves complex interactions of molecular mechanisms that control gene expression and function without altering the underlying DNA sequence. These epigenetic modifications can significantly affect the onset and progression of HCC. This review summarizes recent research on the epigenetic regulation of HBV persistent infection and HBV-HCC development, including DNA methylation, histone modification, RNA modification, non-coding RNA, etc. Enhanced knowledge of these mechanisms will offer fresh perspectives and potential targets for intervention tactics in HBV-HCC.

TCR-like bispecific antibodies toward eliminating infected hepatocytes in HBV mouse models

Therapeutics for eradicating hepatitis B virus (HBV) infection are still limited and current nucleos(t)ide analogs (NAs) and interferon are effective in controlling viral replication and improving liver health, but they cannot completely eradicate the hepatitis B virus and only a very small number of patients are cured of it. The TCR-like antibodies recognizing viral peptides presented on human leukocyte antigens (HLA) provide possible tools for targeting and eliminating HBV-infected hepatocytes. Here, we generated three TCR-like antibodies targeting three different HLA-A2.1-presented peptides derived from HBV core and surface proteins. Bispecific antibodies (BsAbs) were developed by fuzing variable fragments of these TCR-like mAbs with an anti-CD3ϵ antibody. Our data demonstrate that the BsAbs could act as T cell engagers, effectively redirecting and activating T cells to target HBV-infected hepatocytes in vitro and in vivo. In HBV-persistent mice expressing human HLA-A2.1, two infusions of BsAbs induced marked and sustained suppression in serum HBsAg levels and also reduced the numbers of HBV-positive hepatocytes. These findings highlighted the therapeutic potential of TCR-like BsAbs as a new strategy to cure hepatitis B.

Circulating HBsAg-specific B cells are partially rescued in chronically HBV-infected patients with functional cure

It is well established that humoral immunity targeting hepatitis B virus surface antigen (HBsAg) plays a critical role in viral clearance and clinical cure. However, the functional changes in HBsAg-specific B cells before and after achieving functional cure remain poorly understood. In this study, we characterized circulating HBsAg-specific B cells and identified functional shifts and B-cell epitopes directly associated with HBsAg loss. The phenotypes and functions of HBV-specific B cells in patients with chronic HBV infection were investigated using a dual staining method and the ELISpot assay. Epitope mapping was performed to identify B cell epitopes associated with functional cure. Hyperactivated HBsAg-specific B cells in patients who achieved HBsAg loss were composed of enriched resting memory and contracted atypical memory fractions, accompanied by sustained co-expression of multiple inhibitory receptors and increased IL-6 secretion. The frequency of HBsAb-secreting B cells was significantly increased after achieving a functional cure. The rHBsAg displayed a weaker immunomodulatory effect on B cells than rHBeAg and rHBcAg in vitro. Notably, sera from patients with HBsAg loss reacted mainly with peptides S60, S61, and S76, suggesting that these are dominant linear B-cell epitopes relevant for functional cure. Intriguingly, patients reactive with S76 showed a higher frequency of the HLA class II DQB1*05:01 allele. Taken together, HBsAg-specific B cells were partially restored in patients after achieving a functional cure. Functional cure-related epitopes may be promising targets for developing therapeutic vaccines to treat HBV infection and promote functional cure.

Berberine promotes K48-linked polyubiquitination of HNF4α, leading to the inhibition of HBV replication

The current antiviral agents for the treatment of chronic infection with hepatitis B virus (HBV) do not completely remove covalently closed circular DNA (cccDNA) and integrated viral DNA fragments from patients. Berberine is an isoquinoline alkaloid extracted from various plants and has been reported to inhibit the replication of various types of DNA. In this study, we tested the effects of berberine and its derivatives on HBV infection. Berberine inhibited viral core promoter activity at the highest level among the compounds tested and suppressed HBV production and cccDNA synthesis in primary human hepatocytes and HBV-infected HepG2-NTCP cells at an EC50 value of 3.6 μM and a CC50 value of over 240.0 μM. Compared with other viral promoter activities, berberine treatment potently downregulated core promoter activity and reduced protein levels, but not RNA levels, of hepatic nuclear factor 4α (HNF4α), which primarily enhances enhancer II/core promoter activity. Furthermore, berberine treatment enhanced K48-linked, but not K63-linked, polyubiquitination and subsequent proteasome-dependent degradation of HNF4α. These results suggest that berberine enhances the polyubiquitination- and proteasome-dependent degradation of HNF4α and then inhibits HBV replication via the suppression of core promoter activity. The development of antiviral agents based on berberine may contribute to the amelioration of HBV-related disorders, regardless of the presence of residual cccDNA or integrated viral DNA fragments.

Advanced siRNA delivery in combating hepatitis B virus: mechanistic insights and recent updates

Hepatitis B virus (HBV) infection is a major health problem, causing thousands of deaths each year worldwide. Although current medications can often inhibit viral replication and reduce the risk of liver carcinoma, several obstacles still hinder their effectiveness. These include viral resistance, prolonged treatment duration, and low efficacy in clearing viral antigens. To address these challenges in current HBV treatment, numerous approaches have been developed with remarkable success. Among these strategies, small-interfering RNA (siRNA) stands out as one of the most promising therapies for hepatitis B. However, naked siRNAs are vulnerable to enzymatic digestion, easily eliminated by renal filtration, and unable to cross the cell membrane due to their large, anionic structure. Therefore, effective delivery systems are required to protect siRNAs and maintain their functionality. In this review, we have discussed the promises of siRNA therapy in treating HBV, milestones in their delivery systems, and products that have entered clinical trials. Finally, we have outlined the future perspectives of siRNA-based therapy for HBV treatment.

A therapeutic HBV vaccine containing a checkpoint modifier enhances CD8+ T cell and antiviral responses

In patients who progress from acute hepatitis B virus (HBV) infection to a chronic HBV (CHB) infection, CD8+ T cells fail to eliminate the virus and become impaired. A functional cure of CHB likely requires CD8+ T cell responses different from those induced by the infection. Here we report preclinical immunogenicity and efficacy of an HBV therapeutic vaccine that includes herpes simplex virus (HSV) glycoprotein D (gD), a checkpoint modifier of early T cell activation, that augments CD8+ T cell responses. The vaccine is based on a chimpanzee adenovirus serotype 6 (AdC6) vector, called AdC6-gDHBV2, which targets conserved and highly immunogenic regions of the viral polymerase and core antigens fused to HSV gD. The vaccine was tested with and without gD in mice for immunogenicity, and in an AAV8-1.3HBV vector model of antiviral efficacy. The vaccine encoding the HBV antigens within gD stimulates potent and broad CD8+ T cell responses. In a surrogate model of HBV infection, a single intramuscular injection achieved pronounced and sustained declines of circulating HBV DNA copies and HBV surface antigen; both inversely correlated with HBV-specific CD8+ T cell frequencies in spleen and liver.